Hematopoietic stem/progenitor cell (HSPC) based gene therapy holds great promise to provide long-term control of HIV with a single treatment. Like HAART, it is essential to combine multiple drugs to effectively suppress HIV and prevent drug resistant HIV escape mutants. The overall hypothesis of this proposal is that stable introduction of highly potent combinations of anti-HIV genes capable of inhibiting multiple early and late steps of HIV viral lifecycle into HSPC will provide lifelong protection from HIV infection The safety and efficacy of anti-HIV HSPC gene therapy strategies, including inhibition of HIV, lowering of viral load and selective growth advantage of protected cells and prevention of resistance will be evaluated in the recently developed human bone marrow, liver and thymus (BLT) transplanted mouse model. Specific aims are 1) To develop novel multi-pronged anti-HIV gene therapeutic lentiviral vectors and characterize therapeutic reagents to inhibit HIV infection in HSPC and their progeny in vitro 2) To determine the long-term anti-gene expression and stable control of HIV through genetically engineered human HSPC transplant in the BLT mouse model. The approach is innovative because it focuses on novel HIV-1 target HSPC protection and the development of novel potent, broad-range early stage and late stage anti-HIV combinations, maximizing the potential to HIV replication not only in HSPC but also all potential target cells. The proposed research is significant because the results may ultimately lead to an innovative, more effective, more convenient, less toxic, safe and more cost effective way of controlling HIV infection than is currently available. The long-term goal is to advance HSPC based gene therapy research and make rapid progress towards providing a new therapy that leads to stable control of HIV by a single treatment.